In an optical image stabilizer (OIS) camera, three components are added to a typical auto focusing (AF) camera. First, the OIS camera includes a gyroscope sensor for sensing tremor. The gyroscope sensor generally has a function of sensing degrees of tilting with respect to two axes (pitch and yaw). Second, the OIS camera includes an actuator for compensating for tilting of the camera when tremor occurs. Third, the OIS camera includes an OIS control large scale integration (LSI) chip for controlling the gyroscope sensor and the actuator.
Among the three components, the gyroscope sensor and the actuator cannot achieve normal performance when the OIS control LSI chip does not correct a variation between products in a manufacturing state. Typically, the OIS control LSI chip necessarily includes a gain amplifying circuit to control the ratio of output to input, and a module manufacturer performs an individual calibration method for each component through the control of the gain amplifying circuit.
To this end, the typical method includes two methods. First, there is a method of manually searching for a gain value so as to provide the same value to all modules. In this case, the processing time can be decreased, but it is difficult to ensure exact OIS performance when the distribution between components is large. Second, there is a method of automatically searching for a gain value through an image test. In the method, although the distribution between components is large, it can be expected to ensure exact OIS performance to some degree. However, the processing time is considerably increased according to gain control resolution, the evaluation method is complicated, and the processing cost is increased.
Therefore, it is difficult to decrease the processing time and to ensure the exact OIS performance using the typical method, and hence it is required to provide a plan capable of solving such problems.